Decentralization of configuration parameters - Phase 0

[jpraynaud]

Why

We need to decentralize the configuration parameters of the Mithril network (protocol parameters and certification parameters - signed entity types and their specific configuration parameters e.g. cardano_transactions_signing_config). In a first phase , we want to implement a full synchronization of the network based on the leader aggregator, and in a second phase have the configuration stored on the Cardano chain.

What

Implement the Phase 0 of the decentralization plan of the configuration parameters for Mithril networks.

Important

No breaking change on the signer must be introduced in this phase

How

• Remove the next_cardano_transactions_signing_config in the /epoch-settings route
• Remove code that is using the next_cardano_transactions_signing_config in the signer
• Prepare a clear mapping of the (configuration parameters,epoch) tuples used in the current protocol (sent by the aggregator)
• Identify necessary refactoring to accomplish the next phases
• Run a successful backward compatibility test

[turmelclem]

mapping of the (configuration parameters,epoch) tuples used in the current protocol (sent by the aggregator) :

Configuration parameter	Node	Epoch + 0	Epoch + 1	Epoch + 2	Epoch + 3
protocol parameters	aggregator (leader)	update local parameters. Persist epoch settings in database	advertise new protocol parameters on /epoch-settings	-	used to aggregate
protocol parameters	aggregator (follower)	-	fetch new protocol parameters on /epoch-settings and persist them	-	used to aggregate
protocol parameters	signer	-	fetch new protocol parameters on /epoch-settings and does signer registration with them	-	used to sign
entity types config	aggregator (leader)	update local parameters. Persist epoch settings in database	advertise new protocol parameters on /epoch-settings - used to aggregate	-	-
entity types config	aggregator (follower)	-	fetch new protocol parameters on /epoch-settings - used to aggregate	-	-
entity types config	signer	---	fetch new protocol parameters on /epoch-settings - use entity types config for signature scheduling - used to sign	-	-